Have been struggling with dynamic labels in timelion using the regex parameter as in Custom label in timelion. I can get it to work in 5.5.0, but the data I need it for is still in 5.3.2. Is that a known 5.3.2 bug?
From what I can tell the label function hasn't changed since 5.0, but it's possibly a bug in 5.3. Can you explain how you're testing the two versions? Why not just upgrade?